Grinding apparatus



9 Sheets-Sheet l ATTORNEY May 25, 1948. A. E. HAMILTON GRINDINGAPPARATUS Filed March 19, 1946 INVENTOR HLFRED .HHIVZ'LT'ON,

E l I J .1 i WHHMMMH HMHH n H IHWMIM H u H .MMM

May 25, 1948. v A. E. HAMILTON GRINDING APPARATUS Filed MaICh 19, 1946ATTORNEY May 25, 1948. A. E. HAMILTON GRlNDING APPARATUS Filed March 19,194e 9 Sheets-Sheet 5 ATTORNEY 9 sheetslsheet 4 Filed March 19, 1946 lBY MMM

' ATTORNEY May 25, 1948. A. E. HAMILTON GRlNDING APPARATUS Filed March19, 1946 9 Sheets-Sheet 5 m wv.

INVENTOR HLFE E. HAMILTON.

ATTORNEY May 25, 1948. A. E. HAMILTON GRINDING APPARATUS Filed March 19,1946 9 Sheets-Sheet 6 INVENTOR HLF'E EJHNILTN.

ATTORNEY May 25, 1948. A E, HAMILTON 2,442,042

GRlNDING APPARATUS Filed March 19, 19.46 9 Sheets-Sheet '7 Ew D 'SU I@ D@l INVENTOR ALFRED E HQMzL TON ATTORN EY May 25, 1948. A. E. HAMILTONGRlNDING APPARATUS Filed March 19, 1946 9 Sheets-Sheet 8 INVENTOR HL H25D 5 Hana TON,

ATTORNEY 9 sheets-sheet 9 Filed March 19, 1946 INVENTOR4 HL/-RED E.HHH/1L roN.

BY m v ATTORNEY Patented May 25,'1948 UNITED s'rAr-r-:s f PATE-NTori-ics dnmnmc arrmrus Alfred E. Hamilton, Pittsburgh, Pa. Anuman March19. 194e, semi No. escaso 11 Claims.

One object of my invention is to provide apvparatus for snagging orgrinding heavy pieces of metal under greater grinding pressures and witha more rapid removal of metal than is possible with various forms ofgrinding machines heretofore employed.

Another object of my invention is to provide an improved mechanism formoving a grinding wheel and a work piece relative to each other,

during grinding operations. A

Still another object of my invention is to provide an improved means formoving a grinding wheel to operative position on a work piece andmaintaining it under desired degrees of grinding pressure. l

A further object of my invention is to provide an improved means andmethod for preventing loading of the grinding surface of the wheel withparticles of metal from the work pieces or with abrasive fines orparticles loosened from the wheel itself.

Figure 1 is a fragmentary schematic plan view of the apparatus; Fig. 2is a side elevational view thereof; Fig. 3 is an elevational view on anenlarged scale of a portion of the table driving apparatus of Fig. 2;Fig. 4 is a sectional view taken on the line IV-IV of Fig. 3; Fig. 5 isan enlarged sectional view taken on the line V-V of Fig. 2 and showingone of the clamping devices for holding a slab on the table; Fig. 6 islan enlarged cross sectional view of a portion of the apparatus of Fig.1; Fig. l is an end view of a portion of the apparatus of Fig. 6; Fig. 8is a view partly in elevation and partly in section looking in thedirection of arrows VIII-VIII of Fig. 6; Fig. 9 is a. fragmentary endview of the apparatus, partly in section, showing a portion of thegrinding wheel relative to the work; Fig. 10 is a sectional plan viewshowing mechanism for oscillating the grinding wheel; Fig. 11 is a faceview, of a control box for the various motors that operate various partsof the machine; Flg.-12 is an end view thereof, partly in section, andFig. 13 is a plan view, partly diagrammatic, showing the controlmechanisms in the box and their relation to the various motors.

The apparatus comprises a foundation or base I2 having pedestals i3 towhich track rails I4 are anchored by means of bolts I5. The table I6 forthe slabs or other work pieces is in the form l (QL 51-38) of a carrierthat is made up of trucks or buggies i1 that are coupled together bybolts Il and haveanged wheels I3 that travel on the track rails I4 whenthe table is driven in to-and-fro directions.

A rack or series of longitudinally-aimed racks 2| (Fig. 4) are securedto the under surfaces of the buggies by screws 22. The table is drivenalong the tracks i4 by a gear wheel 23 (Figs. 3 and 4) that meshes withthe rack. The gear wheel 23 is driven from a motor 24 (Fig. l), througha reducer 25, that drives a pinion shaft 23 which carries a pinion 21that meshes with a gear wheel 23 whose shaft is provided with a pinion23 (Fig.

l5 3) that meshes with the gear wheel 23 to drive the same. The motor 24will preferably be of the direct current and reversible type so that thetable can be driven in both directions to carry the work pieces' past agrinding wheel that will be hereinafter described.

The floor surface beneath the track rails is sloped toward one end sothat the water used in grinding and the detritus and grindings willdrain into a sump 3| from which they will be removed.

25 A grinder-supporting carriage 32' (Figs. 6-'7-8) is mounted on a base33 that extends laterally of the table as shown more clearly in Fig. l,the carriage being supported on anti-friction bearings 34. As shown moreclearly in Figs. 6 and 8,

the carriage 32 is reciprocated by a reversible motor 35 that is mountedthereon and has a driving pinion 36 which. through a gear wheel 31,drives a gear wheel 33 that has a threaded hub or nut 39 rigidly securedthereto. The nut 35 39 is mounted between the anti-friction bearingsthat are positioned between bearing surfaces 4| and 42 that are carriedby the carriage 32.

The nut 39 has threaded engagement with a screw 43 that is rigidly heldin bearings 44 and 45 that are carried by the base 33. It will be seenthat as the motor 35 is driven in its forward and reverse directions,the carriage 32 will be reciprocated transversely of the table, on thebearings at 34, to move a grinding wheel 46 that is mounted on thecarriage 32 back and forth across slabs or other work pieces on thetable.

A housing 41 of generally cylindrical form is rigidly supported on thecarriage 32 and contains bearing rings 43 which support a ring 49 foroscillating movement. The ring rigidly carries at its lower end a member5|, by means of studs or screws 52. The member 5l is connected to a link53 which is reciprocated as hereinafter described, to oscillate the ring49. vA rocking frame 54 is pivotally supported in the frame, and a waterspray directed against the grinding wheelby a pipe 50. A motor 51 fordriving the grinding wheel is mounted on a base plate 58 that isslidably supported on the rocking frame 54 and is adjustedlongitudinally of the rocker -frame by a screw 59,v to control'l thebelt tension. The motor 51 has a pair of pulleys 6I that, through belts62, drive pulleys 63 on the shaft 60 of the grinding wheel 46.

As above stated, the carriage 32 is reciprocated by the motor to movethe grinding wheel 15 46 transversely of a slab 65 (Figs. 5 and 9), asthe trucks I1 of the table are moved along the track rails I4. Therocking frame 54 is oscillated in a vertical plane (Fig. 6) by a pistoncontained within a, cylinder 66 to which uid under 20 pressure isadmitted through a pipe 61, the piston rod being pivotally connected at68 to the frame 64. The lower end of the cylinder has`a ball-and-'socketconnection at 69 with'the carriage 52, so that the piston and cylinderwill 25 accommodate themselves to the arcv through which the rockingframe 54 is moved.

Fluid pressure is directed through the pipe 61 to hold 'the grindingwheel 46 against the work lating and vibratory movement while thecarriage 32 is being reciprocated to move the grinding wheel 48 to andfro across the work piece, in order to prevent loading of the grindingsurface of the wheel46 by bits of removed metal or crushed nes from thegrinding wheel, to thereby maintain the effectiveness of the wheel. Thecorners of the wheel will first be worn away by this oscillating motion,leaving the abrading surface ofthe wheel in a somewhat convex shape, andit has been found that the oscillating and vibratory movements hereafterreferred to assist in removing the grindings from the surface of thewheel and the work piece.

This oscillatory movement is provided by the mechanism shown moreclearly in Figs. 2, 8 and 10 and comprises (a gear case 85 that issecured to the carriage 32, and a base 86 for a motor 81. The motor 81drives the gearing through a belt 88, the belt tension being adjustableby a screw 89. The belt 88 drives a pulley 9| that is mounted on a shaft92 which carries a gear wheel 93 that, in turn, drives a gear wheel 94mounted on a shaft 95 (Fig. 10). The shaft 95 has an enlarged end 96that is supported in a bearing 91 which has lan internally toothed gearring 96 rigidly mounted therein. The enlarged end 96 serves as a housingfor agear wheel 99 anda shaft IIII that is rigidly secured to the gearpiece With 8 desired pressure, While the Carriage 30 wheel. The gearwheel 99 meshes with the gear 32 is being reciprocated. vIn order toprevent too great tilting of the frame 54 and consequentl dropping ofthe grinding wheel, I providea hanger in the form of a chain 1I thatwill nor-',

3ring 9,8, soa-that when the gear wheel 94 is being irotated, the'g'earwheel 99 and its shaft |8I will aiso be rotated about their individualaxes Ywhich are offset from the axis of the shaft 95.

mally be slack during a; grinding operation but The shaft iol has acrank arm |02 that carwhich will limit the downward movement of thegrindingy wheel under theiiuid pressure force when it has passed theedges of the work piece 65. The chain 1| is connected at its lower endto a stud 12 on the rocker frame and at its upper 40 end extends over asprocket wheel 13 that is keyed to a shaft 14 which also has keyedthereto a worm wheel 15. The worm wheel has mesh engagement with a worm16 which, when turned by its shaft 16a and hand wheel 16h, will shorten45 cut off at the pipe 61, the rocking frame may tilt in a. clockwisedirection under weight of the motor 51, to lift the wheel from the work,or pressure can be admitted to the upper side of the piston through apipe 11 which pipe will serve as of the cylinder when pressure is beingadmitted through the pipe 61 to move the grinding .wheel against a workpiece.

As shown more clearly in Fig. 5, the slabs or 'a means for exhausting:fluid from the upper end 65 other work pieces are releasably held onthe table by.clamping screws 18 placed at suitable intervals and havingthreaded engagement with upstanding shoulders 19 on the trucks I1, thetrucks also having anges or shoulders 8| at their opposite edges.Clamping blocks or bars 82 have 85 holes to receive reduced ends 63 ofthe clamping screwsland are recessed in their inner surfaces to receivehandle-like extensions 84 that are carried by the inner ends of thescrews whereby the screws can be oscillated to move the clamping members82 into and out of engagement with the edge of the slab and to hold itfirmly against the shoulder 8|.

The ring 49, upon which the rocking frame 54 is pivotally supported, isgiven a combined oscilries a crank pin |93 on which the outer end of thelink 53 is journaled, the other end of the link being pivotallyconnected to the ring 49 (Figs. 6 and 8).

It will be seen that when the shaft 95 is being driven by the motor 81,the movement of the shaft |0I around the axis of the shaft 95 willimpart an oscillatory or rocking movement to thering 49 and that therewill be a simultaneous vibratory motion imparted to the llink 53 and thering 49, through rotation of the gear wheel 99 in the ring 95 andconsequent rotation of the shaft I0| about its own axis. This gives whatmight be called a hypocycloidal motion of the ring 49.

For eillcient and accurate operation of apparatus of this kind, it isnecessary that there be some synchronlsm of operation, particularly withrespect to the table-driving motor 24 and the motor 35 that reciprocatesthe grinding wheel transversely of the table and the work piece thereon.It is also desirable that there be automatic control of these motors,with respect to the starting and stopping and the reversal thereof. Forinstance, when the grinding wheel 46 is being reciprocated transverselyof the path of travel of the work piece, the reciprocating movementswill be in timed relation to the traveling movements of the table I1.For example, at the extreme outward position of the grinding wheel 46and its carriage 32, a limit switch will be automatically actuated toreverse the motor 35 that drives the carriage, and at this time, aswitch will be closed to set the table-driving motor 24 in operation, tomove the work table I1 one step. Similarly, at the end of the reversemovement of the grinding wheel and its carriage 32, its motor will bestopped and reversed. and the table-moving motor will again be energizedto advance the table another step.

The limit switches that control the reciprocating movements of thecarriage 32 and the grinding wheel are adjustable so that the length -ofstroke can be varied to suit various widths of work pieces. The limitswitches which. control the table-driving motor 24 are also adjustableso that the motor can be started, stopped, and reversed at proper times,at all lengths of I reciprocatory strokes of the grinding wheel. To

zontal slot |08 to receive an arm |01 that is carried by the carriage orcasing 32 so that this arm |01 will operate certain of the switchesduring reciprocating movements of the carriage 32. Shafts |09 and ||0are journaled in the end walls of the box |04, the shaft |09 having areduced extension I that extends into the shaft ||0 to give stability tothese shafts and to Ipermit rotation of either shaft relative to theother by hand wheels ||2 and |I3 respectively. The

y shafts are held in assembled relation by a nut ||4 that is threaded onto the reduced extension and the shafts are longitudinally shift- ,ableas a unit in the box for a purpose hereinafter explained.

A trip arm ||5 has threaded connection with the shaft |09 so that it,together with the shafts |09-||0, will be shifted by the pusher arm |01at desired intervals. Similarly', a trip arm ||6 has threaded connectionwith the shaft H0, for adjustment longitudinally thereof. A cammingcollar ||1, of split form, is tightly secured to the shaft |09 by atightening screw ||8 and a similar cam collar ||9 is clamped to theshaft ||0 by a screw that extends through the split parts of the collar.The front faces of the members 5|| 6 lie against the front wall of the`box |04 and are thereby held against rotation during turning of thescrew shafts |09| |0.

The trip arms ||5 and ||6 carry pointers |2| and |22 respectively, thatproject through a slot in the front wall of the box and register withscales on the front wall of the box which show the spacing of the triparms and hence the points at which the carriage 32 will, through the arm|01, operate the control switches during reciprocating movements of thegrinding wheel.

The camming collar ||1 trips a limit switch |23 that controls the motor35,. at a predetermined point in the travel of the carriage 32 and itsarm |01 in one direction. The point of travel at which this actuation/0fthe switch is effected is determined by the point at which the trip arm||5 is adjusted on its shaft |09 and hence the point at which the arm|01 actuates the shaft in that direction. Similarly, the shafts |09| I0will be pushed in the opposite direction by the arm |01 on the returnstroke of the carriage 32 and the grinding wheel. The arm |01 will shiftthe trip arm ||6 and the shafts, to effect operation of a switch |24that also controls the motor 35 which reciprocates the carriage 32 andthe grinding wheel. It will be seen that these switches both controlcircuits-through a reversing starter |25 and a rheostat |26 to the motor35 to stop the same and to again start it in the opposite direction ateach end of a reciprocating stroke. The adjustment of the arms ||5 andtransversely movable carriage.

H6 is for adapting the length of reciprocating stroke to the width ofthe work pieces.

Hand wheels |21 and |28 are provided for adjusting limit switches |29and |30 respectively with respect to the camming collars ||1||9 so thatthe table-driving motor 24 will be stopped, started and reversed inpredetermined relation to the reciprocatory movements of the carriage32. To this end, the switches |29 and |30 control a circuit through areverser and motor starter |3| and a rheostat |32.

When the arm |01 strikes the trip arm ||6 on backward movement of thegrinding wheel and its carriage 32, the switch |24 will be actuated bythe camming collar I6 to close the circuit and the switch arm |23released to allow that portion of the circuit to be broken, therebyeffecting a reversal of current in the reversing starter |25. At thistime, the collar ||9 has actuated the switch lever at |30 therebycompleting the circuit through the reversing starter |3| and causing themotor 24 to start and run only momentarily, the speed of the Vmotorbeing regulated by the rheostat |32. The rheostat is adjusted to-control the length of travel of the table upon tripping of the limitswitch |30, this speed being more or less variable according to thespeed of the reciprocating carriage 32.

During these operations, the switch |29 ordinarily will have beenadjusted back by turning of the knob |21 so that it will not be actuatedduring regular forward grinding movements. This limit switch |29 is heldin reserve for controlling the intermittent movements of the table inits backward direction, in which case the switch |30 will be adjusted toan inoperative position by its knob |28. Since the limit switches |23and |24 are fixedly fastened to the box and limit switches |29 and |30are adjustable, the relation between |23 and |29 can be varied and therelative positions of the switches I 24 and |30 also changed. Therefore,the intermittent movement of the table driven by the motor 24 isadjustable with respect to the reciprocating motion of the In otherwords, the switch |30 can be adjusted to trip just before the wheel `hasfinished its grinding movement across the slab, or after the wheel hasfully completed `such movement, and the limit switch |29 will beoperative in a like manner during backward movement of the table.

As shown in Fig. 11, push-button controls are provided at the front ofthe control box. At |34, there is push-button control of the motor 35.

At |36 is the push-button control for starting and stopping the motor 81that operates the vibrating or hypocycloidal device for oscillating thegrinding wheel. At |31, there is push-button control for starting andstopping the motor 51 that rotates the grinding wheel. At |38 is thepush-'button station for starting and stopping the table-driving motor24, through the reversing starter |3| and the rheostat |32. Anacross-theline switch is provided at |39 for starting a motor |40 thatdrives a pump (not shown) which will furnish a grinding solution to thegrinding wheel.

In order to control the operation of the piston in the cylinder 66, andhence the pressure of the grinding wheel on the work, I provide a handlelever |4| and a four-way valve |42 for controlling the admission of airto the upper and lower ends of the cylinder 66. yIt will be understoodthat the pipes 61 and 11 are of flexible hose-like form and ofsuiiicient length to permit the travel of the carriage and the cylinder66 relative to the control box I 04. At one position oi! the valve |42,air will -be admitted to the upper end oi' the piston and exhausted fromthe lower end thereof, while at the opposite position, the duid pressurewill be admitted to the lower end of the piston to swing the rockingframe 54 in a direction to move the grinding wheelagainst the work. Apressure regulator |43 is provided in the air line |44 to control thepressure to the underside of the piston in the cylinder 66 and hence thegrinding pressure. A cam disc |45 is rigidly secured to the extendedrotary barrel |48 of the valve |42 in position to engage a pressureregulating pin |41 that operates within the regulating valve |43 to varythe grinding pressure. This disc is rotatably adjustable in order tolimit the grinding pressure to a desired predetermined maximum degree.

I claim as my invention:

l. Grinding apparatus comprising a table for a work piece, a grindingwheel mounted on an axis that is approximately parallelto the path oftravel of the table, means for reciprocating the grinding wheelcrosswiseof the table, means for advancing the table past the grindingwheel, in step-by-step movements, a device actuated by the reciprocatingmeans, for controlling the movements of the table, and means foroscillating the axis of the grinding wheel in a plane perpendicular tothe plane of the table, during said crosswise movements.

ZifGrinding apparatus comprising a table for a wafgpiece, a grindingwheel mounted on an axis tliatlisl approximately parallel to the path oftravel ai the table, automatically operable means for reciprocating thegrinding wheel crosswise of the table, means for advancing the tablepast the grinding Wheel, in step-by-step movements, a device actuated bythe reciprocating means, for controlling the movements of the table,means for oscillating the axis of the grinding wheel in a planeperpendicular to the plane of the table during said crosswise movements,and means for manually controlling the said'crosswise movements of thegrinding wheel independently of the automatically operable means.

3. Grinding apparatus comprising a table for a work piece, an electricmotor for moving the table, a grinding wheel mounted on an axis that isapproximately parallel to the path of travel of the table, an electricmotor for reciprocatingthe gr'nding wheel crosswise of the table, and acontrol device operated in timed relation to said reciprocatorymovements, for periodically energizing and deenergizing thetable-driving motor.

4. Grinding apparatus comprising a table for a work piece, an electricmotor for moving the table, a grinding wheel mounted on an axis that isapproximately parallel to the path of travel of the table, an electricmotor for reciprocating the grinding wheel crosswise of the table, and acontrol device operated in timed relation to said reciprocatorymovements, for periodically energizing and deenergizing thetable-driving motor,

`the said device being operative at the end of each reciprocatorymovement of the grinding wheel.

5. Grinding apparatus comprising a table for a work piece, an electricmotor for moving the table, a grinding wheel mounted on an axis that isapproximately parallel to the path of travel of the table, an electricmotor for reciprocatingA the grinding wheel crosswise oi' the table,means for automatically reversing the second-named motor at the end ofeach reciprocatory stroke, and a control device operated in timedrelation to said reciprocatory movements, for periodically energizingand deenergizing the table-driving motor, the said device beingoperative at the end gheazh reciprocatory movement of the grinding 6.Grinding apparatus comprising a table ior motor, the. said device beingoperative at the end of each reciprocatory movement of the grindingwheel, and means for manually controlling the length of reciprocatorystroke of the grinding wheel independently oi the said automatic means.

'7. Grinding apparatus comprising a carrier for a work piece, a grindingwheel mounted on an axis that is approximately parallel to the plane ofthe carrier, means for imparting relative Itraveling movements to thecarrier and the grinding wheel, in directions transversely of andapproximately parallel to the axis of the grinding wheel, means forrotating the wheel, and means for oscillating the grinding wheel in aplane that is perpendicularto the plane of the carrier and on an axisthat iaparalleltetheend l faces of the grinding Wheeland which lsspacad'a substantial distance from-the grinding plane.

8. Grinding apparatus comprising a carriage that is movable in a givenpath, a bearing on the carriage, a bearing ring in said bearing,rotatable about an axis that is parallel to said path, a rocking frameextending through said ring and pivoted thereon, intermediate its ends,on an axis transverse to the ilrst-named axis, a grinding wheelrotatably mounted on the outer end of said frame, a motor mounted on theinner end of said frame and having driving connection with the grindingwheel, a cylinder and a piston respectively connected to the inner endof the frame and the carriage, the said connections being pivotal, meansfor supplying iiuid pressure to said cylinder to rock the frame on itsaxis, and means foroscillating the frame about the axis of the bearingring.

9. Grinding apparatus comprising a carriage that is movable in a givenpath, a bearing on the carriage, a bearing ring in 'said bearing,rotatable about an axis thatis parallel to said path, a rocking iframeextending through said ring and piv- 1 oted thereon, intermediate itsends, on an axis ing ring, Va second motor on the carriage, and` meansoperative by said second motor for imparting reciprocating movements tothe carriage, in said path.

l0. 'I'he method of grinding, which comprises moving a work piece past agrinding wheel while rotating the wheel on an axis that is approximatelyparallel to the path oi travel oi the work piece, while oscillating thegrinding wheel on an axis that is Itransverse to its axis of rotationand parallel to the face of the work piece and While bodily moving thegrinding wheel on the work piece in directions transversely of saidpath, the said axes of oscillation being spaced a substantial distanceabove the plane of contact by the grinding wheel with the work piecewhen the wheel is positioned above the work piece.

11. The method of grinding, which comprises moving a work piece past agrinding wheel while rotating the wheel on an axis that is approxi?mately parallel to the path of travel of the work piece, whileoscillating the grinding wheel on an axis that is transverse to itsaxis, of rotation and parallel to the face of the work piece and whilebodily moving the grinding wheel on the work piece in directionstransversely of said path, and moving the work piece step-by-step inperiodic relation to the transverse movements of the grinding wheel.

ALFRED E. HAMILTON.

10 REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 411,839 Taft Oct. 1, 1889 725,142Robinson Apr. 14, 1903 1,866,212 Hunford et al July 5, 1932 1,952,334Robinson Mar. 27, 1934 2,308,843 Wilson Jan. 19, 1943 2,403,341 CarlsonJuly 2, 1946 FOREIGN PATENTS Number Country Date 340,910 Great BritainJan. 8, 1931

